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HTTP streaming, with bidirectional emulation

HTTP streaming is a technique based on using a long-lived HTTP connection between a client and a server with a chunked transfer encoding. Usually it only allows unidirectional flow of messages from server to client but with Centrifugo bidirectional emulation layer it may be used as a full-featured fallback or alternative to WebSocket.

HTTP-streaming connection endpoint in Centrifugo is:

/connection/http_stream
info

This transport is only implemented by our Javascript SDK. Internally it uses modern Fetch and Readable Streams API. HTTP-streaming fully supports binary transfer using our Protobuf protocol.

Here is an example how to use JavaScript SDK with WebSocket as the main transport and HTTP-streaming transport fallback:

Use HTTP-streaming with bidirectional emulation as a fallback for WebSocket in JS SDK
const transports = [
    {
        transport: 'websocket',
        endpoint: 'ws://localhost:8000/connection/websocket'
    },
    {
        transport: 'http_stream',
        endpoint: 'http://localhost:8000/connection/http_stream'
    }
];
const centrifuge = new Centrifuge(transports);
centrifuge.connect()
danger

Make sure allowed_origins are properly configured.

Options​

http_stream​

Boolean, default: false.

Enables HTTP streaming endpoint. And enables emulation endpoint (/emulation by default) to accept emulation HTTP requests from clients.

config.json
{
    ...
    "http_stream": true
}

http_stream_max_request_body_size​

Default: 65536 (64KB)

Maximum allowed size of a initial HTTP POST request in bytes.